Exploitation of self-consistency and differences between volume images and interpreted spatial/volumetric context

ABSTRACT

Self-consistency and/or differences between volume images and interpreted spatial/volumetric context may be exploited for improving seismic imaging and estimation of attributes of geobodies, in accordance with one or more embodiments. Exemplary embodiments allow exploitation of positional and/or shape discrepancies and/or similarities of geobodies in image volumes associated with a geologic model of a geologic volume of interest to improve the accuracy of the geologic model and/or the image volumes. Constraints associated with the geologic volume of interest may be determined and/or utilized to confirm and/or specify dependencies between attributes that are potentially associated with individual geobodies.

FIELD OF THE DISCLOSURE

This disclosure relates to improving seismic imaging and estimation ofattributes and/or rock properties of geobodies by exploitingself-consistency and/or differences between volume images andinterpreted spatial/volumetric context.

BACKGROUND OF THE DISCLOSURE

Seismic imaging and subsurface interpretation are performed to obtain,as accurately as possible, a geologic model of a subsurface volume ofthe earth. Conventional industry workflows generally include thefollowing serial process steps: (a) process the seismic data into 3Dseismic image volumes of the subsurface volume of the earth; (b) extractattributes (e.g., velocity, Poisson's ratio, density, acousticimpedance, etc.) at each subsurface point in the subsurface volume ofthe earth using tabulated and other known petrophysical data and rockproperties; (c) interpret the geometry of the 3D seismic image volumes,log information, and geological analogs on an interpretation workstationto obtain the structure, stratigraphic, and geologic morphology; and (d)construct a geological and reservoir subsurface model from extractedattributes and the obtained structure, stratigraphic, and geologicmorphology.

Conventional industry workflows have limited reconciliation/integrationof earth models used in imaging with interpretation of structure andstratigraphy, and with reservoir properties from seismic estimation.Each process step has inherent uncertainties and non-uniqueness thatcannot be well defined quantitatively. Consequently, it is difficult toquantify the uncertainties and non-uniqueness of geological reservoirmodels yielded by conventional industry workflows. Most industryworkflows resort to geostatistical methods to estimate uncertainties andnon-uniqueness. Even so, there is no guarantee that the resulting,probabilistic models are consistent with all the data utilized ingenerating the models.

SUMMARY

One aspect of the disclosure relates to a computer-implemented methodfor constraining a range of rock properties and confirming and/orspecifying dependencies between rock properties of geobodies associatedwith a geologic volume of interest. The method may include identifyinggeobody representations that represent geobodies in the geologic volumeof interest. The geobody representations may be interpreted fromindividual ones of a plurality of multi-offset-multi-attribute imagevolumes. A given one of the multi-offset-multi-attribute image volumesmay (1) correspond to one of the offset stacks, angle stacks, or azimuthstacks, (2) be associated with one of the attributes, and (3) includegeobody representations of geobodies present in the geologic volume ofinterest. The method may include receiving assignments of geobody typescorresponding to the identified geobody representations based ongeologic principles, stratigraphic principles, and/or an analogdatabase. The method may include determining one or more propertyconstraints for one or more rock properties of the geobodies in an earthmodel and/or a velocity model associated with the geologic volume ofinterest by constraining a range of rock properties associated withindividual ones of the geobodies based on geologic principles,stratigraphic principles, and/or an analog database. The method mayinclude verifying the one or more property constraints based on one ormore of dependencies between the one or more rock properties, well datalogs, data derived from well data logs, or local geological knowledge ofthe geological volume of interest.

Another aspect of the disclosure relates to a system configured toconstrain a range of rock properties and confirming and/or specifyingdependencies between rock properties of geobodies associated with ageologic volume of interest. The system may include one or moreprocessors configured to execute computer program modules. The computerprogram modules may include a geobody interpretation module, a propertyconstraints module, and/or other modules. The geobody interpretationmodule may be configured to identify geobody representations thatrepresent geobodies in the geologic volume of interest. The geobodyrepresentations may be interpreted from individual ones of a pluralityof multi-offset-multi-attribute image volumes. A given one of themulti-offset-multi-attribute image volumes may (1) correspond to one ofthe offset stacks, angle stacks, or azimuth stacks, (2) be associatedwith one of the attributes, and (3) include geobody representations ofgeobodies present in the geologic volume of interest. The geobodyinterpretation module may be further configured to receive assignmentsof geobody types corresponding to the identified geobody representationsbased on geologic principles, stratigraphic principles, and/or an analogdatabase. The property constraints module may be configured to determineone or more property constraints for one or more rock properties of thegeobodies in an earth model and/or a velocity model associated with thegeologic volume of interest by constraining a range of rock propertiesassociated with individual ones of the geobodies based on geologicprinciples, stratigraphic principles, and/or an analog database. Theproperty constraints module may be further configured to verify the oneor more property constraints based on one or more of dependenciesbetween the one or more rock properties, well data logs, data derivedfrom well data logs, or local geological knowledge of the geologicalvolume of interest.

Yet another aspect of the disclosure relates to a computer-readablestorage medium having instructions embodied thereon. The instructionsmay be executable by a processor to perform a method for constraining arange of rock properties and confirming and/or specifying dependenciesbetween rock properties of geobodies associated with a geologic volumeof interest. The method may include identifying geobody representationsthat represent geobodies in the geologic volume of interest. The geobodyrepresentations may be interpreted from individual ones of a pluralityof multi-offset-multi-attribute image volumes. A given one of themulti-offset-multi-attribute image volumes may (1) correspond to one ofthe offset stacks, angle stacks, or azimuth stacks, (2) be associatedwith one of the attributes, and (3) include geobody representations ofgeobodies present in the geologic volume of interest. The method mayinclude receiving assignments of geobody types corresponding to theidentified geobody representations based on geologic principles,stratigraphic principles, and/or an analog database. The method mayinclude determining one or more property constraints for one or morerock properties of the geobodies in an earth model and/or a velocitymodel associated with the geologic volume of interest by constraining arange of rock properties associated with individual ones of thegeobodies based on geologic principles, stratigraphic principles, and/oran analog database. The method may include verifying the one or moreproperty constraints based on one or more of dependencies between theone or more rock properties, well data logs, data derived from well datalogs, or local geological knowledge of the geological volume ofinterest.

These and other features and characteristics of the present technology,as well as the methods of operation and functions of the relatedelements of structure and the combination of parts and economies ofmanufacture, will become more apparent upon consideration of thefollowing description and the appended claims with reference to theaccompanying drawings, all of which form a part of this specification,wherein like reference numerals designate corresponding parts in thevarious figures. It is to be expressly understood, however, that thedrawings are for the purpose of illustration and description only andare not intended as a definition of the limits of the technology. Asused in the specification and in the claims, the singular form of “a”,“an”, and “the” include plural referents unless the context clearlydictates otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a system configured to improve seismic imaging andestimation of attributes and/or rock properties of geobodies byexploiting self-consistency and/or differences between volume images andinterpreted spatial/volumetric context, in accordance with one or moreembodiments.

FIG. 2 illustrates a method for improving seismic imaging and estimationof attributes and/or rock properties of geobodies by exploitingself-consistency and/or differences between volume images andinterpreted spatial/volumetric context, in accordance with one or moreembodiments.

DETAILED DESCRIPTION

The present technology may be described and implemented in the generalcontext of a system and computer methods to be executed by a computer.Such computer-executable instructions may include programs, routines,objects, components, data structures, and computer software technologiesthat can be used to perform particular tasks and process abstract datatypes. Software implementations of the present technology may be codedin different languages for application in a variety of computingplatforms and environments. It will be appreciated that the scope andunderlying principles of the present technology are not limited to anyparticular computer software technology.

Moreover, those skilled in the art will appreciate that the presenttechnology may be practiced using any one or combination of hardware andsoftware configurations, including but not limited to a system havingsingle and/or multi-processer computer processors system, hand-helddevices, programmable consumer electronics, mini-computers, mainframecomputers, and the like. The technology may also be practiced indistributed computing environments where tasks are performed by serversor other processing devices that are linked through one or more datacommunications networks. In a distributed computing environment, programmodules may be located in both local and remote computer storage mediaincluding memory storage devices.

Also, an article of manufacture for use with a computer processor, suchas a CD, pre-recorded disk or other equivalent devices, may include acomputer program storage medium and program means recorded thereon fordirecting the computer processor to facilitate the implementation andpractice of the present technology. Such devices and articles ofmanufacture also fall within the spirit and scope of the presenttechnology.

Referring now to the drawings, embodiments of the present technologywill be described. The technology can be implemented in numerous ways,including for example as a system (including a computer processingsystem), a method (including a computer implemented method), anapparatus, a computer readable medium, a computer program product, agraphical user interface, a web portal, or a data structure tangiblyfixed in a computer readable memory. Several embodiments of the presenttechnology are discussed below. The appended drawings illustrate onlytypical embodiments of the present technology and therefore are not tobe considered limiting of its scope and breadth.

FIG. 1 illustrates a system 100 configured to improve seismic imagingand estimation of attributes and/or rock properties of geobodies byexploiting self-consistency and/or differences between volume images andinterpreted spatial/volumetric context, in accordance with one or moreembodiments. More specifically, the system 100 may be configured toexploit positional and/or shape discrepancies and/or similarities ofgeobodies in image volumes associated with earth models of a geologicvolume of interest to improve the accuracy of the earth models, velocitymodels used for pre-stack imaging, and/or the image volumes. In someembodiments, the system 100 may be configured to constrain a range ofrock properties and confirm and/or specify dependencies between rockproperties of geobodies associated with the geologic volume of interest.The system 100 may be configured to construct an earth model usingmulti-offset-multi-attribute image volumes and identified geobodiesassociated with a geologic volume of interest, according to someembodiments. Seismic data may be re-imaged with an updated model.

A geologic volume of interest may include one or more “overburdens.” Anoverburden may generally be described as a geologic section above a bed,refractor, and/or reflector. Examples of an overburden may includematerial lying above an ore or valuable deposit and pressing down on it,loose unconsolidated material above bedrock, and/or other overburdens.An overburden may be associated with a velocity model and/or other modelthat can be used for re-imaging.

A geologic volume of interest may include one or more targets such as,for example, reservoir targets. Detailed analysis may be performed onsuch targets to determine information relating to geobodies and/or rockproperties, in accordance with one or more embodiments. Depending on thespecific information sought, a geologic volume of interest may includean entire geologic section from the surface to the target interval overan area of interest, or a geologic volume of interest may be confined toa specific target interval.

As depicted in FIG. 1, the system 100 may include electronic storage102, a user interface 104, one or more information resources 106, atleast one processor 108, and/or other components. In some embodiments,the electronic storage 102 comprises electronic storage media thatelectronically stores information. The electronic storage media of theelectronic storage 102 may include system storage that is providedintegrally (i.e., substantially non-removable) with the system 100and/or removable storage that is removably connectable to the system 100via, for example, a port (e.g., a USB port, a firewire port, etc.) or adrive (e.g., a disk drive, etc.). The electronic storage 102 may includeone or more of optically readable storage media (e.g., optical disks,etc.), magnetically readable storage media (e.g., magnetic tape,magnetic hard drive, floppy drive, etc.), electrical charge-basedstorage media (e.g., EEPROM, RAM, etc.), solid-state storage media(e.g., flash drive, etc.), and/or other electronically readable storagemedia. The electronic storage 102 may store software algorithms,information determined by the processor 108, information received viathe user interface 104, information received from the informationresources 106, and/or other information that enables the system 100 tofunction as described herein. The electronic storage 102 may be aseparate component within the system 100, or the electronic storage 102may be provided integrally with one or more other components of thesystem 100 (e.g., the processor 108).

The user interface 104 is configured to provide an interface between thesystem 100 and a user through which the user may provide information toand receive information from the system 100. This enables data, results,and/or instructions and any other communicable items, collectivelyreferred to as “information,” to be communicated between the user andthe system 100. As used herein, the term “user” may refer to a singleindividual or a group of individuals who may be working in coordination.Examples of interface devices suitable for inclusion in the userinterface 104 include one or more of a keypad, buttons, switches, akeyboard, knobs, levers, a display screen, a touch screen, speakers, amicrophone, an indicator light, an audible alarm, and/or a printer. Inone embodiment, the user interface 104 actually includes a plurality ofseparate interfaces.

It is to be understood that other communication techniques, eitherhard-wired or wireless, are also contemplated by the present technologyas the user interface 104. For example, the present technologycontemplates that the user interface 104 may be integrated with aremovable storage interface provided by the electronic storage 102. Inthis example, information may be loaded into the system 100 fromremovable storage (e.g., a smart card, a flash drive, a removable disk,etc.) that enables the user to customize the implementation of thesystem 100. Other exemplary input devices and techniques adapted for usewith the system 100 as the user interface 104 include, but are notlimited to, an RS-232 port, RF link, an IR link, modem (telephone, cableor other). In short, any technique for communicating information withthe system 100 is contemplated by the present technology as the userinterface 104.

The information resources 106 include one or more sources of informationrelated to the geologic volume of interest. By way of non-limitingexample, one of information resources 106 may include seismic dataacquired at or near the geological volume of interest, informationderived therefrom, and/or information related to the acquisition. Suchseismic data may include source wavefields and receiver wavefields. Theseismic data may include individual traces of seismic data (e.g., thedata recorded on one channel of seismic energy propagating through thegeological volume of interest from a source), offset stacks, anglestacks, azimuth stacks, and/or other data. The information derived fromthe seismic data may include, for example, geologic models from seismicdata representing energy that has propagated through the geologic volumeof interest from one or more energy sources to one or more energyreceivers, image volumes from the geologic model representing geobodiespresent in the geologic volume of interest, and/or other information.Individual ones of the image volumes may correspond to individual onesof the offset stacks, angle stacks, or azimuth stacks. Informationrelated to the acquisition of seismic data may include, for example,data related to the position and/or orientation of a source of seismicenergy, the positions and/or orientations of one or more detectors ofseismic energy, the time at which energy was generated by the source anddirected into the geological volume of interest, and/or otherinformation.

The information resources 106 may include information other thanseismic-related data associated with the geologic volume of interest.Examples of such information may include information relating togravity, magnetic fields, resistivity, magnetotelluric information,radar data, well logs, rock properties, geological analog data, and/orother information.

The processor 108 is configured to provide information processingcapabilities in the system 100. As such, the processor 108 may includeone or more of a digital processor, an analog processor, a digitalcircuit designed to process information, an analog circuit designed toprocess information, a state machine, and/or other mechanisms forelectronically processing information. Although the processor 108 isshown in FIG. 1 as a single entity, this is for illustrative purposesonly. In some implementations, the processor 108 may include a pluralityof processing units. These processing units may be physically locatedwithin the same device or computing platform, or the processor 108 mayrepresent processing functionality of a plurality of devices operatingin coordination.

As is shown in FIG. 1, the processor 108 may be configured to executeone or more computer program modules. The one or more computer programmodules may include one or more of a communications module 110, a modelmodule 112, an imaging module 114, a geobody interpretation module 116,a synthetic seismic data module 118, a property constraints module 120,and/or other modules. The processor 108 may be configured to executemodules 110, 112, 114, 116, 118, and/or 120 by software; hardware;firmware; some combination of software, hardware, and/or firmware;and/or other mechanisms for configuring processing capabilities on theprocessor 108.

It should be appreciated that although the modules 110, 112, 114, 116,118, and 120 are illustrated in FIG. 1 as being co-located within asingle processing unit, in implementations in which the processor 108includes multiple processing units, one or more of the modules 110, 112,114, 116, 118, and/or 120 may be located remotely from the othermodules. The description of the functionality provided by the differentmodules 110, 112, 114, 116, 118, and/or 120 described below is forillustrative purposes, and is not intended to be limiting, as any of themodules 110, 112, 114, 116, 118, and/or 120 may provide more or lessfunctionality than is described. For example, one or more of the modules110, 112, 114, 116, 118, and/or 120 may be eliminated, and some or allof its functionality may be provided by other ones of the modules 110,112, 114, 116, 118, and/or 120. As another example, the processor 108may be configured to execute one or more additional modules that mayperform some or all of the functionality attributed below to one of themodules 110, 112, 114, 116, 118, and/or 120. As yet another example, theprocessor 108 may be configured to execute one or more modules that mayperform some or all of the functionality attributed to one or moremodules described in co-pending U.S. patent application Ser. No.13/017,995, filed Jan. 31, 2011, and entitled “Extracting GeologicInformation from Multiple Offset Stacks and/or Angle Stacks,” which isincorporated herein by reference.

The communications module 110 may be configured to receive information.Such information may be received from the information resources 106, theuser via the user interface 104, the electronic storage 102, and/orother information sources. Examples of received information may includeseismic data and information derived therefrom, information related tothe acquisition of seismic data, offset stacks, angle stacks, azimuthstacks, geologic models, image volumes, and/or other information.Information received by the communications module 110 may be utilized byone or more of modules 112, 114, 116, 118, and/or 120. Examples of somesuch utilizations are described below. The communication module 110 maybe configured to transmit information to one or more other components ofthe system 100.

The model module 112 may be configured to generate and/or otherwiseobtain one or more models associated with a geologic volume of interest.The one or more models may be single- or multi-dimensional. Examples ofsuch models may include an earth model, a velocity model, and/or othermodels associated with a geologic volume of interest. An earth model mayinclude a numerical representation of at least one property (e.g.,seismic velocity, density, attenuation, anisotropy, and/or otherproperty) as a function of location within the geologic volume ofinterest. A velocity model may include a spatial distribution ofvelocity through which raypaths obeying Snell's law can be traced. Avelocity model may refer to a model used in migration such as, forexample, depth migration. A velocity model may be referred to as avelocity cube. In some implementations, the model module 112 may beconfigured to obtain a velocity model, an earth model, and/or othermodel from seismic data representing energy that has propagated throughthe geologic volume of interest from one or more energy sources to oneor more energy receivers. The seismic data may include one or moreoffset stacks, one or more angle stacks, one or more azimuth stacks,and/or other seismic data.

The model module 112 may be configured to update an earth model, avelocity model, and/or other model using one or more inversiontechniques. Performing an inversion may include deriving from data(e.g., seismic data, field data, and/or other data) a model to describethe subsurface of a geologic volume of interest that is consistent withthe data. An inversion may include solving for a spatial distribution ofparameters which could have produced an observed set of measurements.Examples of such parameters may include registration data, seismic eventtimes, and/or other parameters.

The one or more inversion techniques may include one or more modelingrealizations and/or comparisons to observed data. The one or moreinversion techniques may include imaging with multiple models,holography, interferometry, and/or other inversion techniques. By was ofnon-limiting example, the one or more inversion techniques may include atime travel inversion. One type of time travel inversion may be atomographic inversion. A tomographic inversion may include determiningthe subsurface velocity distribution using tomographic methods.Tomographic methods may include determining velocity and/or reflectivitydistribution from a multitude of observations using combinations ofsource and receiver locations, and/or determining the resistivitydistribution from conductivity measurements using a transmitter in onewell and a receiver in another well.

The one or more inversion techniques may be based on registration dataand/or assigned geobody types of geobodies included within the geologicvolume of interest. Examples of geobody types may include one or more ofa geological surface, a fluvial channel, a point bar, a reef, a fault,an unconformity, a delta, a dike, a sill, a salt body, a crevasse splay,a reservoir flow unit, a fluid contact, a turbidite channel, a turbiditesheet, and/or other geobody types.

The model module 112 may be configured to utilize one or more propertyconstraints associated with geobodies to update an earth model, avelocity model, and/or other models. Property constraints are describedin further detail in connection with the property constraints module120. The model module 112 may be configured to generate and/or otherwiseobtain an updated earth model, an updated velocity model, and/or othermodel, wherein one or more rock properties of geobodies represented inthe updated earth model, the updated velocity model, and/or other modelhave been constrained based on assigned geobody types of identifiedgeobodies represented in the updated earth model, the updated velocitymodel, and/or other model. Examples of rock properties may include oneor more of velocity, anisotropy, density, acoustic properties, elasticproperties, petrophysical properties, fluid properties, reservoirproperties, geologic description, lithologic classification, and/orother rock properties.

The imaging module 114 may be configured to perform imaging, and/orgenerate and/or otherwise obtain one or more image volumes. Imagevolumes may correspond to individual ones of the offset stacks, anglestacks, azimuth stacks, and/or other information. Image volumes mayrepresent geobodies present in a geologic volume of interest. An imagevolume may include a multi-offset-multi-attribute image volume.

In accordance with some embodiments, the imaging module 114 may beconfigured to generate and/or otherwise obtain a plurality ofmulti-offset-multi-attribute image volumes from seismic data. A givenone of the multi-offset-multi-attribute image volumes may correspond toone of the offset stacks, angle stacks, and/or azimuth stacks. A givenone of the multi-offset-multi-attribute image volumes may be associatedwith at least one attribute. Examples of attributes may include one ormore of coherence, Hilbert transform, amplitude, instantaneousfrequency, spectral decomposition, attenuation, impedance, Poisson'sratio, offset dependency of seismic response, reflection angle and/orazimuth dependency of seismic response, dip, magnitude, curvature,roughness, dip azimuth, spectral shape, and/or other attributes. A givenone of the multi-offset-multi-attribute image volumes may includegeobody representations of geobodies present in the geologic volume ofinterest. The imaging module 114 may be configured to generate and/orotherwise obtain one or more updated multi-offset-multi-attribute imagevolumes based on the updated earth model and/or the updated velocitymodel.

According to some embodiments, the imaging module 114 may be configuredto generate and/or otherwise obtain a plurality ofmulti-offset-multi-attribute image volumes from synthetic seismic data.Synthetic seismic data is described further in connection with thesynthetic seismic data module 118. A given one of themulti-offset-multi-attribute image volumes may correspond to one of anoffset stack, an angle stack, or an azimuth stack of the syntheticseismic data. A given one of the multi-offset-multi-attribute imagevolumes may be is associated with a seismic attribute. A given one ofthe multi-offset-multi-attribute image volumes may include geobodyrepresentations of geobodies previously unidentified in the updatedearth model and/or velocity model.

The geobody interpretation module 116 may be configured to determine,identify, and/or receive geobody interpretations. In some embodiments,the geobody interpretations may be received via the user interface 104.Geobody interpretations may be based on one or more image volumes, whichmay include one or more multi-offset-multi-attribute image volumes. Thegeobody interpretations may include identified geobodies having geobodyrepresentations in the image volumes. The geobody interpretations mayinclude geobody types assigned to the identified geobodies.

The geobody interpretation module 116 may be configured to obtainregistration data associated with individual identified geobodies indifferent ones of the image volumes based on the assigned geobody types.The registration data for a given geobody may represent a spatialposition, a shape of the given geobody, discrepancies and/orsimilarities between geobody representations of the given geobody indifferent ones of the image volumes, and/or other information associatedwith the given geobody.

The geobody interpretation module 116 may be configured to verifyidentified geobodies based on a comparison between synthetic seismicdata and the seismic data used to obtain the image volumes. Syntheticseismic data is described in further detail in connection with thesynthetic seismic data module 118. The geobody interpretation module 116may be configured to determine and/or receive a reinterpretation of afirst geobody responsive to the verifying of the identified geobodiesindicating an interpretation of the first geobody is inaccurate. Thereinterpretation of the first geobody may include a new assignment ofgeobody type for the first geobody. The geobody interpretation module116 may be configured to obtain new registration data for the firstgeobody corresponding to the reinterpretation.

The geobody interpretation module 116 may be configured to determineand/or receive rock properties and/or geobody types assigned to theidentified geobodies. The rock properties and/or geobody types may beassigned consistent with geologic principles, stratigraphic principles,and/or an analog database. As mentioned above, rock properties mayinclude, for example, one or more of velocity, anisotropy, density,acoustic properties, elastic properties, petrophysical properties, fluidproperties, reservoir properties, geologic description, lithologicclassification, and/or other rock properties.

The geobody interpretation module 116 may be configured to performconstrained seismic inversions. A constrained inversion may refer to alimitation on the output values of rock properties through the inversionprocess, an inversion over a limited seismic frequency bandwidth, and/orother constrained inversions. The geobody interpretation module 116 maybe configured to perform a constrained seismic inversion to determinerock properties of the identified geobodies. The geobody interpretationmodule 116 may be configured to perform a constrained seismic inversionto identify other geobodies with associated rock properties in order toreduce differences between observed seismic data and synthetic data.According to some embodiments, a constrained seismic inversion may bestabilized by the constrained rock properties of the identifiedgeobodies.

The synthetic seismic data module 118 may be configured to generateand/or otherwise obtain synthetic seismic data. The synthetic seismicdata may correspond to an earth model, a velocity model, and/or othermodel. Synthetic seismic data may include an artificial seismicreflection record generated by assuming that a particular waveformtravels through an assumed model. Synthetic seismic data may not berestricted by dimensionality of a corresponding model. Synthetic seismicdata may not be limited by the complexity of mathematics and/orincorporated physical properties used to describe the correspondingmodel and/or represent the wave propagation. Synthetic seismic data mayinclude propagation through a single- or multi-dimensional elastic modelwith attenuation and velocity anisotropy.

The property constraints module 120 may be configured to determineand/or otherwise obtain one or more property constraints for one or morerock properties of the geobodies in an earth model, a velocity model,and/or other model associated with the geologic volume of interest. Theproperty constraints module 120 may be configured to determine and/orotherwise obtain the one or more property constraints by constraining arange of rock properties associated with individual ones of thegeobodies based on geologic principles, stratigraphic principles, and/oran analog database. The property constraints module 120 may beconfigured to verify the property constraints based on one or more ofdependencies between the one or more rock properties, well data logs,data derived from well data logs, local geological knowledge of thegeological volume of interest, and/or other information.

FIG. 2 illustrates a method 200 for improving seismic imaging andestimation of attributes and/or rock properties of geobodies byexploiting self-consistency and/or differences between volume images andinterpreted spatial/volumetric context, in accordance with one or moreembodiments. The operations of the method 200 presented below areintended to be illustrative. In some embodiments, the method 200 may beaccomplished with one or more additional operations not described,and/or without one or more of the operations discussed. For example, themethod 200 may include one or more operations described in co-pendingU.S. patent application Ser. No. 13/017,995, filed Jan. 31, 2011, andentitled “Extracting Geologic Information from Multiple Offset Stacksand/or Angle Stacks,” which has been incorporated herein by reference.Additionally, the order in which the operations of the method 200 areillustrated in FIG. 2 and described below is not intended to belimiting.

In some embodiments, the method 200 may be implemented in one or moreprocessing devices (e.g., a digital processor, an analog processor, adigital circuit designed to process information, an analog circuitdesigned to process information, a state machine, and/or othermechanisms for electronically processing information). The one or moreprocessing devices may include one or more devices executing some or allof the operations of the method 200 in response to instructions storedelectronically on an electronic storage medium. The one or moreprocessing devices may include one or more devices configured throughhardware, firmware, and/or software to be specifically designed forexecution of one or more of the operations of the method 200.

As depicted in FIG. 2, the method 200 may include a loop 202, a loop204, and/or other loops. Operations included in the loop 202 and theloop 204 may be performed separately or in conjunction with each other.Information may be passed between the loop 202 and the loop 204 tocompliment one or more operations included therein.

The loop 202 may relate to imaging and/or modeling improvement. Morespecifically, the loop 202 may relate to exploiting positional and/orshape discrepancies and/or similarities of geobodies in image volumesassociated with earth models of a geologic volume of interest to improvethe accuracy of the earth models, velocity models used for pre-stackimaging, and/or the image volumes. The loop 202, may relate toconstructing an earth model using multi-offset-multi-attribute imagevolumes and identified geobodies associated with a geologic volume ofinterest. Seismic data may be re-imaged with an updated model. One ormore operations in the loop 202 may be iteratively repeated such thatmagnitudes of the discrepancies are decreased and/or to make otherimaging and/or modeling refinements.

At operation 206, a velocity model and/or an earth model may be obtainedand/or updated. A velocity model and/or an earth model may be obtainedfrom seismic data representing energy that has propagated through thegeologic volume of interest from one or more energy sources to one ormore energy receivers. The seismic data may include one or more of aplurality of offset stacks, a plurality of angle stacks, or a pluralityof azimuth stacks. The earth model and/or the velocity model may beupdated using travel time inversion techniques based on registrationdata and assigned geobody types associated with geobodies within thegeologic volume of interest. One or more rock properties of geobodiesrepresented in the updated earth model and/or velocity model may havebeen constrained based on assigned geobody types of identified geobodiesrepresented in the updated earth model and/or velocity model. Syntheticseismic data corresponding to the updated earth model and/or velocitymodel may be obtained at operation 206. The model module 112 and/or thesynthetic seismic data module 118 may perform some or all of operation206, in accordance with some embodiments.

At operation 208, a plurality of multi-offset-multi-attribute imagevolumes may be obtained from seismic data and/or synthetic seismic data.Where the plurality of multi-offset-multi-attribute image volumes areobtained from seismic data, a given one of themulti-offset-multi-attribute image volumes (1) may correspond to one ofthe offset stacks, angle stacks, or azimuth stacks, (2) may beassociated with at least one attribute, and/or (3) may include geobodyrepresentations of geobodies present in the geologic volume of interest.Where the plurality of multi-offset-multi-attribute image volumes areobtained from synthetic seismic data a given one of themulti-offset-multi-attribute image volumes (1) may correspond to one ofan offset stack, an angle stack, or an azimuth stack of the syntheticseismic data, (2) may be associated with a seismic attribute, and (3)may include geobody representations of geobodies previously unidentifiedin the updated earth model and/or velocity model. Updatedmulti-offset-multi-attribute image volumes may be generated at operation208 based on the updated earth model and/or the updated velocity model(see operation 206). This may include implementing one or more changesin image processing parameterization. The imaging module 114 may performoperation 208, in accordance with some embodiments.

At operation 210, geobody interpretations are determined and/orreceived. The geobody interpretations may be based on themulti-offset-multi-attribute image volumes. The geobody interpretationsmay include identified geobodies having geobody representations in themulti-offset-multi-attribute image volumes and geobody types assigned tothe identified geobodies. A constrained seismic inversion may beperformed at operation 210 to determine rock properties of theidentified geobodies, and/or to identify other geobodies with associatedrock properties in order to reduce differences between observed seismicdata and the synthetic data. The constrained seismic inversion may bestabilized by the constrained rock properties of the identifiedgeobodies. The geobody interpretation module 116 may perform operation210, in accordance with some embodiments.

At operation 212, registration data associated with individualidentified geobodies in different ones of themulti-offset-multi-attribute image volumes is obtained. The registrationdata may be obtained based on the assigned geobody types. Theregistration data for a given geobody may representing a spatialposition, a shape of the given geobody, and/or discrepancies and/orsimilarities between geobody representations of the given geobody indifferent ones of the multi-offset-multi-attribute image volumes. Thegeobody interpretation module 116 may perform operation 212, inaccordance with some embodiments.

The loop 204 may relate to interpretation of rock properties within thegeobodies. More specifically, the loop 204 may relate to constraining arange of rock properties and confirming and/or specifying dependenciesbetween rock properties of geobodies associated with a geologic volumeof interest. In exemplary embodiments, loop 204 may provide constrainedinversion results for the rock properties of some or all of thegeobodies in the geological volume of interest. One or more operationsin the loop 204 may be iteratively repeated to eliminate and/or refineone or more property constraints, and/or to make other interpretiverefinements.

At operation 214, geobody representations that represent geobodies inthe geologic volume of interest are identified. The geobodyrepresentations may be interpreted from individual ones of themulti-offset-multi-attribute image volumes. The geobody interpretationmodule 116 may perform operation 214, in accordance with someembodiments.

At operation 216, assignments of geobody types corresponding to theidentified geobody representations are determined and/or received. Thegeobody types may be determined and/or received based on geologicprinciples, stratigraphic principles, and/or an analog database. Thegeobody interpretation module 116 may perform operation 216 inaccordance with some embodiments.

At operation 218, one or more property constraints for one or more rockproperties of the geobodies in the earth model and/or velocity model maybe constrained by a range of rock properties associated with individualones of the geobodies based on geologic principles, stratigraphicprinciples, and/or an analog database. One or more property constraintsfor one or more rock properties of the geobodies in the earth modeland/or velocity model may be estimated from well data logs, data derivedfrom well data logs, and/or local geological knowledge of the geologicalvolume of interest. In exemplary embodiments, such estimates may bebased on extrapolation from local well measurements. The propertyconstraints module 120 may perform operation 218, in accordance withsome embodiments.

At operation 220, the one or more property constraints are verified.Using at least one of the verified one or more property constraints, aconstrained seismic inversion may be performed (see, e.g., operation210) to determine rock properties of all the identified geobodies,and/or to identify all other geobodies with associated rock propertiesin the geological volume of interest in order to reduce differencesbetween observed seismic data and the synthetic data. The constrainedseismic inversion may be stabilized by the constrained rock propertiesof the identified geobodies. The property constraints module 120 mayperform operation 220, in accordance with some embodiments.

Although the technology has been described in detail for the purpose ofillustration based on what is currently considered to be the mostpractical and preferred embodiments, it is to be understood that suchdetail is solely for that purpose and that the technology is not limitedto the disclosed embodiments, but, on the contrary, is intended to covermodifications and equivalent arrangements that are within the spirit andscope of the appended claims. For example, it is to be understood thatthe present technology contemplates that, to the extent possible, one ormore features of any embodiment can be combined with one or morefeatures of any other embodiment.

What is claimed is:
 1. A computer-implemented method for constraining arange of rock properties and confirming and/or specifying dependenciesbetween rock properties of geobodies associated with a geologic volumeof interest, the method comprising: identifying geobody representationsthat represent geobodies in the geologic volume of interest, the geobodyrepresentations being interpreted from individual ones of a plurality ofmulti-offset-multi-attribute image volumes, wherein a given one of themulti-offset-multi-attribute image volumes (1) corresponds to one of theoffset stacks, angle stacks, or azimuth stacks, (2) is associated withone of the attributes, and (3) includes geobody representations ofgeobodies present in the geologic volume of interest; receivingassignments of geobody types corresponding to the identified geobodyrepresentations based on one or more geologic principles, one or morestratigraphic principles, and/or an analog database; determining one ormore property constraints for one or more rock properties of thegeobodies in an earth model and/or a velocity model associated with thegeologic volume of interest by constraining a range of rock propertiesassociated with individual ones of the geobodies based on the one ormore geologic principles, the one or more stratigraphic principles,and/or geological analog database; and verifying the one or moreproperty constraints based on one or more of dependencies between theone or more rock properties, one or more well data logs, or data derivedfrom the well data logs, of the geological volume of interest.
 2. Themethod of claim 1, further comprising iteratively repeating (1) theidentifying of geobody representations, (2) the receiving of assignmentsof geobody types corresponding to the identified geobodyrepresentations, (3) the determining of one or more propertyconstraints, and (4) the verifying of the property constraints.
 3. Themethod of claim 1, further comprising utilizing the one or more propertyconstraints associated with the geobodies to update the earth modeland/or the velocity model.
 4. The method of claim 1, wherein theassigned geobody types comprise one or more of a geological surface, afluvial channel, a point bar, a reef, a fault, an unconformity, a delta,a dike, a sill, a salt body, a crevasse splay, a reservoir flow unit, afluid contact, a turbidite channel, or a turbidite sheet.
 5. The methodof claim 1, wherein the attributes comprise one or more of coherence,Hilbert transform, amplitude, instantaneous frequency, spectraldecomposition, attenuation, impedance, Poisson's ratio, offsetdependency of seismic response, reflection angle and/or azimuthdependency of seismic response, dip, magnitude, curvature, roughness,dip azimuth, or spectral shape.
 6. The method of claim 1, wherein therock properties comprise one or more of velocity, anisotropy, density,one or more acoustic properties, one or more elastic properties, one ormore petrophysical properties, one or more fluid properties, one or morereservoir properties, a geologic description, or a lithologicclassification.
 7. A system configured to constrain a range of rockproperties and confirming and/or specifying dependencies between rockproperties of geobodies associated with a geologic volume of interest,the system comprising: one or more processors configured to executecomputer program modules, the computer program modules comprising: ageobody interpretation module configured to identify geobodyrepresentations that represent geobodies in the geologic volume ofinterest, the geobody representations being interpreted from individualones of a plurality of multi-offset-multi-attribute image volumes,wherein a given one of the multi-offset-multi-attribute image volumes(1) corresponds to one of the offset stacks, angle stacks, or azimuthstacks, (2) is associated with one of the attributes, and (3) includesgeobody representations of geobodies present in the geologic volume ofinterest; the geobody interpretation module being further configured toreceive assignments of geobody types corresponding to the identifiedgeobody representations based on one or more geologic principles, one ormore stratigraphic principles, and/or a geological analog database; aproperty constraints module configured to determine one or more propertyconstraints for one or more rock properties of the geobodies in an earthmodel and/or a velocity model associated with the geologic volume ofinterest by constraining a range of rock properties associated withindividual ones of the geobodies based on the one or more geologicprinciples, the one or more stratigraphic principles, and/or an analogdatabase; and the property constraints module being further configuredto verify the one or more property constraints based on one or more ofdependencies between the one or more rock properties, well data logs, ordata derived from well data logs, of the geological volume of interest.8. The system of claim 7, wherein the geobody interpretation moduleand/or the property constraints module are further configured toiteratively repeat (1) the identifying of geobody representations, (2)the receiving of assignments of geobody types corresponding to theidentified geobody representations, (3) the determining of one or moreproperty constraints, and (4) the verifying of the property constraints.9. The system of claim 7, further comprising a model module configuredto utilize the one or more property constraints associated with thegeobodies to update the earth model and/or the velocity model.
 10. Thesystem of claim 7, wherein the assigned geobody types comprise one ormore of a geological surface, a fluvial channel, a point bar, a reef, afault, an unconformity, a delta, a dike, a sill, a salt body, a crevassesplay, a reservoir flow unit, a fluid contact, a turbidite channel, or aturbidite sheet.
 11. The system of claim 7, wherein the attributescomprise one or more of coherence, Hilbert transform, amplitude,instantaneous frequency, spectral decomposition, attenuation, impedance,Poisson's ratio, offset dependency of seismic response, reflection angleand/or azimuth dependency of seismic response, dip, magnitude,curvature, roughness, dip azimuth, or spectral shape.
 12. The system ofclaim 7, wherein the rock properties comprise one or more of velocity,anisotropy, density, one or more acoustic properties, one or moreelastic properties, one or more petrophysical properties, one or morefluid properties, one or more reservoir properties, a geologicdescription, or a lithologic classification.
 13. A non-transitory,computer-readable storage medium having instructions embodied thereon,the instructions being executable by a processor to perform a method forconstraining a range of rock properties and confirming and/or specifyingdependencies between rock properties of geobodies associated with ageologic volume of interest, the method comprising: identifying geobodyrepresentations that represent geobodies in the geologic volume ofinterest, the geobody representations being interpreted from individualones of a plurality of multi-offset-multi-attribute image volumes,wherein a given one of the multi-offset-multi-attribute image volumes(1) corresponds to one of the offset stacks, angle stacks, or azimuthstacks, (2) is associated with one of the attributes, and (3) includesgeobody representations of geobodies present in the geologic volume ofinterest; receiving assignments of geobody types corresponding to theidentified geobody representations based on one or more geologicprinciples, one or more stratigraphic principles, and/or geologicalanalog database; determining one or more property constraints for one ormore rock properties of the geobodies in an earth model and/or avelocity model associated with the geologic volume of interest byconstraining a range of rock properties associated with individual onesof the geobodies based on the one or more geologic principles, the oneor more stratigraphic principles, and/or an analog database; andverifying the one or more property constraints based on one or more ofdependencies between the one or more rock properties, one or more welldata logs, or data derived from the well data logs, of the geologicalvolume of interest.
 14. The non-transitory, computer-readable storagemedium of claim 13, wherein the method further comprises iterativelyrepeating (1) the identifying of geobody representations, (2) thereceiving of assignments of geobody types corresponding to theidentified geobody representations, (3) the determining of one or moreproperty constraints, and (4) the verifying of the property constraints.15. The non-transitory, computer-readable storage medium of claim 13,wherein the method further comprises utilizing the one or more propertyconstraints associated with the geobodies to update the earth modeland/or the velocity model.
 16. The non-transitory, computer-readablestorage medium of claim 13, wherein the assigned geobody types compriseone or more of a geological surface, a fluvial channel, a point bar, areef, a fault, an unconformity, a delta, a dike, a sill, a salt body, acrevasse splay, a reservoir flow unit, a fluid contact, a turbiditechannel, or a turbidite sheet.
 17. The non-transitory, computer-readablestorage medium of claim 13, wherein the attributes comprise one or moreof coherence, Hilbert transform, amplitude, instantaneous frequency,spectral decomposition, attenuation, impedance, Poisson's ratio, offsetdependency of seismic response, reflection angle and/or azimuthdependency of seismic response, dip, magnitude, curvature, roughness,dip azimuth, or spectral shape.
 18. The non-transitory,computer-readable storage medium of claim 13, wherein the rockproperties comprise one or more of velocity, anisotropy, density, one ormore acoustic properties, one or more elastic properties, one or morepetrophysical properties, one or more fluid properties, one or morereservoir properties, a geologic description, or a lithologicclassification.